An improved compact MIMO antenna for wireless applications with band-notched characteristics

A quad-element highly compact multiple input multiple output (MIMO) antenna with notched characteristics is presented for wireless applications. The notch band characteristic is obtained by integrated two-quarter wavelength folded strip resonators into the patch antenna. A combination of a modified T-shaped stub and complementary split ring resonator (CSRR) is used to enhance the isolation into the common ground plane. The VSWR bandwidth of designed antenna is 320 MHz (2.30-2.62 GHz) and 6.84 GHz (3.46-10.3 GHz) with minimum isolation of around 18 dB among its antenna elements. The envelope correlation coefficient is <0.03 with an overall size of 32 × 38 mm2.